Frenchie
Jack of all trades
Below I've attached links to other photo's taken during previous trips. I believe one or more of the photo's will show the areas of potential concern. After viewing, please comment.
The first three are still set to private, i think - I get a page asking Richard Leblanc to sign in. The other two work, but aren't the area of concern.
The pipe that runs straight down off of the water heater is not plugged. It is, however, too short. An inspector recommended I lengthen it and route it into the hole where the other drain is.
Then you're okay.
The top end of that pipe, where it connects to the tank (whith the yellow paper's hanging, in your first picture on this thread) is a valve that opens automatically if the tank gets over-pressurized. Sometimes people who don't know any better block the pipe, then it's a hazard.